lttng-modules 2.11.2-1ubuntu0.1 ADT test failure with linux 5.4.0-49.53

[Stefan Bader]

[SRU Justification]

== Impact ==
An upstream change in v5.9 which was backported into all supported releases modified a function which lltng-modules uses. This causes the DKMS compilation to fail for all kernels which carry that fix.

== Fix ==
We add kernel version specific fixup code which allows to compile for previous and newer kernels.

== Testcase ==
DKMS build of lttng-modules will fail without the update and work with all kernels in updates and proposed.

== Regression Potention ==
The DKMS build might still fail (but beside of conditionally handling an additional argument to a function the code is unchanged).

---

Testing failed on:
    amd64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/amd64/l/lttng-modules/20200923_104051_ff54e@/log.gz
    arm64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/arm64/l/lttng-modules/20200921_213835_75690@/log.gz
    ppc64el: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/ppc64el/l/lttng-modules/20200922_003029_2408c@/log.gz
    s390x: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/s390x/l/lttng-modules/20200921_174009_64208@/log.gz

[Stefan Bader (smb)]

  CC [M] /var/lib/dkms/lttng-modules/2.11.2/build/probes/lttng-kprobes.o
In file included from /var/lib/dkms/lttng-modules/2.11.2/build/probes/../probes/define_trace.h:87,
                 from /var/lib/dkms/lttng-modules/2.11.2/build/probes/../instrumentation/events/lttng-module/writeback.h:736,
                 from /var/lib/dkms/lttng-modules/2.11.2/build/probes/lttng-probe-writeback.c:38:
/var/lib/dkms/lttng-modules/2.11.2/build/probes/../probes/lttng-tracepoint-event-impl.h:130:6: error: conflicting types for ‘trace_writeback_queue_io’
  130 | void trace_##_name(_proto);
      | ^~~~~~
/var/lib/dkms/lttng-modules/2.11.2/build/probes/../probes/lttng-tracepoint-event-impl.h:42:2: note: in expansion of macro ‘LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP’
   42 | LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(map, name, map, PARAMS(proto), PARAMS(args))
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/lttng-modules/2.11.2/build/probes/../probes/lttng-tracepoint-event-impl.h:84:2: note: in expansion of macro ‘LTTNG_TRACEPOINT_EVENT_MAP’
   84 | LTTNG_TRACEPOINT_EVENT_MAP(name, name, \
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/lttng-modules/2.11.2/build/probes/../instrumentation/events/lttng-module/writeback.h:376:1: note: in expansion of macro ‘LTTNG_TRACEPOINT_EVENT’
  376 | LTTNG_TRACEPOINT_EVENT(writeback_queue_io,
      | ^~~~~~~~~~~~~~~~~~~~~~
In file included from ./include/trace/events/writeback.h:8,
                 from /var/lib/dkms/lttng-modules/2.11.2/build/probes/lttng-probe-writeback.c:20:
./include/linux/tracepoint.h:233:21: note: previous definition of ‘trace_writeback_queue_io’ was here
  233 | static inline void trace_##name(proto) \
      | ^~~~~~
./include/linux/tracepoint.h:396:2: note: in expansion of macro ‘__DECLARE_TRACE’
  396 | __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
      | ^~~~~~~~~~~~~~~
./include/linux/tracepoint.h:532:2: note: in expansion of macro ‘DECLARE_TRACE’
  532 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
      | ^~~~~~~~~~~~~
./include/trace/events/writeback.h:499:1: note: in expansion of macro ‘TRACE_EVENT’
  499 | TRACE_EVENT(writeback_queue_io,
      | ^~~~~~~~~~~

[Stefan Bader (smb)]

In "Focal update: v5.4.62 upstream stable release" (bug #1895174) the arguments of the trace event writeback_queue_io were changed from 3 to 4 by:

Author: Jan Kara <email address hidden>
Date: Fri May 29 16:08:58 2020 +0200

    writeback: Fix sync livelock due to b_dirty_time processing

    BugLink: https://bugs.launchpad.net/bugs/1895174

    commit f9cae926f35e8230330f28c7b743ad088611a8de upstream.

[Stefan Bader (smb)]

This would be the proposed fix for focal which should also prepare us for the coming hwe kernels as well. For bionic there likely will be a similar change needed. At least to handle hwe-5.4 but potentially the upstream change got backported to 4.15 as well.

[Stefan Bader (smb)]

Focal test build at: https://launchpad.net/~smb/+archive/ubuntu/temp01

Verification in VM:

root@test-f1:/usr/src/lttng-modules-2.11.2# dpkg -l |grep lttng-modules-dkms
ii lttng-modules-dkms 2.11.2-1ubuntu0.2 all Linux Trace Toolkit (LTTng) kernel modules (DKMS)
root@test-f1:/usr/src/lttng-modules-2.11.2# dkms status
lttng-modules, 2.11.2, 5.4.0-48-generic, x86_64: installed
lttng-modules, 2.11.2, 5.4.0-49-generic, x86_64: installed

[Stefan Bader (smb)]

Bionic test build will be at: https://launchpad.net/~smb/+archive/ubuntu/temp01

Verification in VM:

root@test-b1:~# dpkg -l|grep lttng-modules-dkms
ii lttng-modules-dkms 2.10.8-1ubuntu2~18.04.3 all Linux Trace Toolkit (LTTng) kernel modules (DKMS)
root@test-b1:~# dkms status
lttng-modules, 2.10.8, 4.15.0-118-generic, x86_64: installed
lttng-modules, 2.10.8, 4.15.0-119-generic, x86_64: installed
lttng-modules, 2.10.8, 5.4.0-48-generic, x86_64: installed
lttng-modules, 2.10.8, 5.4.0-49-generic, x86_64: installed

[Stefan Bader (smb)]

Xenial test build will be at: https://launchpad.net/~smb/+archive/ubuntu/temp01

Verification in VM:

root@test-x1:~# dpkg -l|grep lttng-modules-dkms
ii lttng-modules-dkms 2.8.0-1ubuntu1~16.04.9 all Linux Trace Toolkit (LTTng) kernel modules (DKMS)
root@test-x1:~# dkms status
lttng-modules, 2.8.0, 4.15.0-118-generic, x86_64: installed
lttng-modules, 2.8.0, 4.15.0-119-generic, x86_64: installed
lttng-modules, 2.8.0, 4.4.0-190-generic, x86_64: installed
lttng-modules, 2.8.0, 4.4.0-191-generic, x86_64: installed

[Christian Ehrhardt  (paelzer)]

Some odd brackets, but that was known and functionally the same.
I added a missing dep3 header on the focal debdiff, but other than that it LGTM.

Sponsored to -unapproved.

[Łukasz Zemczak (sil2100)]

Hello Stefan, or anyone else affected,

Accepted lttng-modules into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.11.2-1ubuntu0.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Stefan Bader (smb)]

ADT testing succeeded against current updates and the new kernel in proposed (http://autopkgtest.ubuntu.com/packages/l/lttng-modules/focal/amd64 (this is amd64, but all other arches are the same)). Marking as verified for focal.

[Łukasz Zemczak (sil2100)]

Hello Stefan, or anyone else affected,

Accepted lttng-modules into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.10.8-1ubuntu2~18.04.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Łukasz Zemczak (sil2100)]

Hello Stefan, or anyone else affected,

Accepted lttng-modules into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.8.0-1ubuntu1~16.04.9 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Stefan Bader (smb)]

ADT testing against the current bionic kernel and the proposed base and hwe kernel all completed successfully: http://autopkgtest.ubuntu.com/packages/l/lttng-modules/bionic/amd64 (link only for amd64 but change is arch indipenant).

[Stefan Bader (smb)]

Same for Xenial, ADT testing now succeeded for current base kernel and the new base and hwe from proposed (http://autopkgtest.ubuntu.com/packages/l/lttng-modules/xenial/amd64).

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for lttng-modules has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package lttng-modules - 2.11.2-1ubuntu0.2

---------------
lttng-modules (2.11.2-1ubuntu0.2) focal; urgency=medium

  * Fix writeback_queue_io() modification (LP: #1896781):
    - d/p/compat-5.9/0001-fix-writeback-queue-io.patch

 -- Stefan Bader <email address hidden> Wed, 23 Sep 2020 18:21:58 +0200

[Launchpad Janitor (janitor)]

This bug was fixed in the package lttng-modules - 2.10.8-1ubuntu2~18.04.3

---------------
lttng-modules (2.10.8-1ubuntu2~18.04.3) bionic; urgency=medium

  * Fix writeback_queue_io() modification (LP: #1896781):
    - d/p/compat-5.9/0001-fix-writeback-queue-io.patch

 -- Stefan Bader <email address hidden> Thu, 24 Sep 2020 16:06:01 +0200

[Launchpad Janitor (janitor)]

This bug was fixed in the package lttng-modules - 2.8.0-1ubuntu1~16.04.9

---------------
lttng-modules (2.8.0-1ubuntu1~16.04.9) xenial; urgency=medium

  * Fix writeback_queue_io() modification (LP: #1896781):
    - d/p/compat-5.9/0001-fix-writeback-queue-io.patch

 -- Stefan Bader <email address hidden> Thu, 24 Sep 2020 18:10:41 +0200